class Point {
  int x,y;
  void setXY(int m, int n){
    x =m;
    y =n;
  }
}

public class Example4_4 {
  public static void main(String[] args) {
    Point p1,p2;
    p1 = new Point();
    p2 = new Point();
    System.out.println("p1的引用"+p1);
    System.out.println("p2的引用"+p2);
    p1.setXY(1111,2222);
    p2.setXY(-100,-200);
    System.out.println("p1的x，y坐标"+p1.x+","+p1.y);
    System.out.println("p2的x，y坐标"+p2.x+","+p2.y);
    p1 = p2;
    System.out.println("将p2的引用赋给p1后：");
    System.out.println("p1的引用"+p1);
    System.out.println("p2的引用"+p2);
    System.out.println("p1的x，y坐标："+p1.x+","+p1.y);
    System.out.println("p2的x，y坐标："+p2.x+","+p2.y);
  }
}
